The swaddling of infants has been practiced since antiquity by people around the world. Swaddling protects an infant from the surrounding environment, allows a caregiver to handle and carry an infant more easily, and has long been thought to comfort and quiet an infant.
This is especially true of “colicky” infants, those who cry at least three hours a day, three days a week, for at least three weeks in a row. Although no specific cause for colic has been identified and many potential remedies have been offered, research has shown that effective swaddling often has a calming effect on crying infants. Research also shows that a swaddled infant tends to be more willing to sleep on her back, which significantly reduces her vulnerability to Sudden Infant Death Syndrome.
The key to effective swaddling appears to reside in a combination of factors. Loosely-swaddled infants tend to be more restless than snugly-swaddled infants, but overly tight swaddling may inhibit breathing. An infant is comforted by having her arms held snugly against her midsection and by having even pressure applied around her torso. Limitations on leg movement help also, but complete immobilization of the legs may promote hip dysplasia. Any pressure against the head is counterproductive. Too thin a wrap may provide inadequate restraint, but too heavy a wrap may overheat the infant.
It is thought that gentle, even pressure around an infant's torso and immobilization of her limbs may simulate the pre-birth environment. Additionally, or alternatively, immobilization of the limbs may keep an infant from startling herself awake by reflexively flailing her limbs in her sleep and striking nearby objects. Pressure against the head is thought to awaken an infant by stimulating the “rooting” response, where the infant reflexively seeks a nipple.
An ideal swaddling implement would therefore provide a means for immobilizing an infant's arms while placing gentle, even pressure on her torso; would restrict leg movement without excessive pressure; and would leave the infant's head unencumbered. In addition, the implement could be made of light fabric so that the infant would not overheat. The implement would be easy to use, allowing a quick, snug wrap without complex folding and tucking.
Unfortunately, presently-available swaddling implements do not provide all of these features. Few people know how to securely and properly wrap an infant in a conventional blanket, and fewer still have the inclination to learn. The traditional “colic band,” a fabric strip that is wrapped around an infant's midsection, may provide some relief but does not properly contain the infant's arms and legs. Other available swaddling implements may be too loose to provide more than insulation, or too may be tight around the legs, or may have a hood that triggers the rooting response.